In the manufacture of brake disks, especially for disk-brake systems in which the brake disk passes between a pair of brake shoes carried by a caliper extending around the outer periphery of the disk, the brake disk generally has a crown portion or outer peripheral strip which constitutes the engagement portion and is formed with opposite surfaces engaged by the respective brake shoes, and a cup-shaped hub portion located inwardly of a crown portion.
The crown portion generally lies in a plane from which the hub portion or disk cup projects to one side.
After formation of the basic disk body, e.g. by forging and/or casting, it is a common practice to finish the braking surfaces of the crown of the disks, generally by a grinding process. This grinding may be a finishing grinding following, for example, a turning or facing operation. Reference to "grinding" herein, as far as the invention is concerned, will be understood to include fine grinding or finish grinding of the surfaces.
In the past, for the grinding of such brake disks, the apparatus which was provided generally could accommodate only a single size of disk. However, since disks are fabricated in lots of different sizes, it is advantageous to be able to grind the disks of different sizes in the different lots in one and the same apparatus.
It has been the practice heretofore to provide disk-grinding machines for this purpose which comprise a feed conveyor, generally a roller conveyor, upon which a succession of brake-disk workpieces are supplied in a predetermined cadence, a discharge conveyor, generally a roller conveyor, on which the ground workpieces are carried off, a grinding machine with grinding tools disposed on opposite sides of a disk introduced into the machine to grind the opposite surfaces thereof as the disk is rotated, and a manipulator or the like for picking up the brake-disk workpiece, carrying it to the grinding machine, removing the ground disk from the machine and placing the ground disks on the discharge-roller conveyor.
While such an apparatus has been found to be highly suitable for the mass or serial production of brake disks, problems have been encountered heretofore with respect to the limited versatility of the apparatus and especially its inability to adjust to various sizes, e.g. diameters of the brake disks.
In general, the apparatus had a so-called machine portal or stand carrying the grinding tools and the respective motors, which was fixedly mounted in the machine frame provided with the holder for the workpiece during the grinding operation. To accommodate the machine to process disks of other sizes, i.e. other lots of brake disks, it was necessary to disassemble and reassemble the apparatus to accommodate the different relative positions of the grinding tools and the holders.
The feed and discharge devices also required adjustment and, as a consequence, the down time of the apparatus was considerable. Clearly this drawback was inconsistent with the high speed operations of the machine and otherwise rendered the apparatus unacceptable for uses in which a number of lot changes might occur with time based upon changes in the diameter or size of the disk.